Waterproofed reenforced paper



Patented Aug. 16, 1932 I UNITEDSTATES' PATENT OFF-ICE GEORGE E. (mans, or ATTLEBORO, mssaonusnrrs. nssreuon TO Amnnroau an- En roacED PAPER comramr, or a'r'rnanono, massacnusm'rsn coar'onanon Olli MASSACHUSETTS warnnrnoornn nnnuroacnn rnrna Application filed Kay 23,

This invention relates to reenforced paper designed more particularly for use as a building paper.

There is now on the market a reenforced E paper consisting oftwo sheets of paper adhesively secured together by a waterproof adhesive and reenforced by unspun fibres of long staple adhesively secured between the two sheets.

w i This reenforced paper now in use is employed for various purposes where a strong durable paper wrapper or protecting cover is desired, and since the sheets of the reenforced paper are secured together by a waterproof adhesive, moisture is prevented from penetrating entirely through the reenforced paper.

It is found however in practice that when this reenforced paper is employed as a building paper it tends towrinkle and shrink upon ex osure to the weather. This is due to the act that the outer face of there enforced paper as constructed heretofore is pervious to moisture and as a result expands when wet and shrinks and wrinkles as it dries while the inner sheet is maintained in a dry condition. As this expanding and shrinking action is repeated underv weather changes it is found that permanent wrinkles so are formed in the outer'sheet of paper and that the entire sheet gradually shrinks. This exerts a drawing or shrinking action on the inner reenforcing sheet and pullsthe marginal edges of the reenforced sheet of building paper loose from the nails or other securing means employed to fasten the reenforced paper to a surface of the building.-

The objectionable shrinking action just mentioned is greater than that produced by a single wetting and drying of the unprotected outer sheet and is produced by the repeated expansion and contraction of the outer sheet caused by the rain and sun over a period of time while the inner sheetof paper is maintained in a dry stretched condition.

This repeated stretching and shrinking of the outer sheet of paper causes it to shift slightly relative to the inner sheet, particularl when the outer sheet shrinks rapidly whi e drying in the hot sun, as under this 1928. Serial No. 279,983.

condition the hot asphaltuin adhesive may be soft enough to permit a slight movement between the sheets of paper. This results in a wrinkling and puckering of the inner sheet and reenforcinrr fibres.

It will therefbre be seen that the successive shrinking action which is responsible for the edges of the reenforced paper pulling loose from the nail heads or other securing means, is due largely to the construction of the multiply building paper in which the outer sheet is unprotected from the rain and sun while the inner sheet is maintained in a dry condition. Having in mind the foregoing, the present mventionrelates toan improved reenforced building paper the outer face of which is rendered water-repellent so that it will not shrink and. pull loose from its fastening .means upon exposure to the weather. 7

The variousijeatures-of the invention will be best understood from the followin description when read iii connection wit the accompanying drawing illustrating the invention.

In the drawing Fig. 1 isa perspective view of means for applying a water-repellent coating to a sheet of paper.

Fig. 2 is a perspective view of a different type of means for applying a water-repellent coating to one face of a reenforced sheet of paper; and

.Fig. 3 is a front view of a sheet of building paper constructed in accordance with the present invention and having one sheet rolled back to show the reenforcement.

As above stated the present invention relates to improvements in reenforced building paper such as shown in Figs. 2 and 3 and-consists of two sheets of paper 10 and 11 which are adhesively secured together by a waterproof adhesive 12 such as asphaltum. The twoly paper thus formed is reenforced longitudinally by the relatively straight un-' spunfibres 13 that extend lengthwise of the staple, and are firmly secured between the sheets of paper by the adhesive 12. While any tough, durable paper may be employed as constituting the sheets 10 and 11, it is found that, what is commercially known as kraft paper, is well adapted for this purpose as it is cheap, strong and tough.

Reenforced waterproofed paper having the construction so far described is strong, tough and durable and can be manufactured at low cost, but as above pointed out when this paper is exposed to the rain and sun it undergoes a successive shrinking action that wrinkles and puckers the inner sheet and fibres and causes the edges of the composite sheet to pull loose from the nails or other securing means.

This difficulty is overcome in accordance with the present invention by rendering. the

outer face of the sheet 11 which is exposed to the weather, water-repellent, and while a mumber of materials for rendering paper waterproof are well known, much difficulty has been experienced in developing a practical coating material'for the present purpose. This is due to the fact that if a penetrating substance such as hot paraflin is applied to the outer face of the multiply waterproof paper it will penetrate through the outer sheet of paper to the inner surface thereof withthe result.that the paraffin will cause the layer of asphaltum 12 between the sheets of paper 10 and ll to release its grip on the treated sheet of paper. If on the other hand a non-penetrating adhesive'such as asphaltum is used to coat the outer face of the multiply paper it will render the paper sticky so that it is-difiicult to handle 3nd can not be unwound from a roll. Further it is important that the moisture-proofing mixture or coating employed be low. in cost, easy to apply, and that it adhere firmly to the paper and present a clean surface to handle.

It is found that highly satisfactoryresults are secured by coating the outer face of the sheet of paper 11 with a mixture consisting of parts-petroleum asphalt and 15 parts paraflin, the mixture being applied to the paper in a hot condition and preferably at only afew degrees above the melt-; ing point of the asphalt so that the mixture will completely coat the surface of the paper without penetrating through to the opposite face of the paper.- .The proportion of asphalt and paraflin used may of course be varied within wide limits, depending upon the nature of the coating desired, and in some cases it may be desirable to add a drying oil such as linseed oil to the other ingredients to make the coating film tougher and more coherent. It will also be apparent that other moisture proofing materials may be employed, but the coating material above described satisfactorily protects the face of the paper and may be applied without appreciably increasing the cost of producing the reenforced paper.

Various means may be employed for applying the water repellent coating to the paper and the coating material is preferably worked or forced into the face of the paper by the roller 18 that dips into the mixture and the excess material is removed by the 1 doctor 19. A second roller 20 which does not dip into the coating material may be employed to rub or force the coating material into the face of the paper, and this roller 20 may be driven at either a faster or a slower speed than the paper 11 to increase its rubbing action. Above the sheet of paper are mounted the backing rollers 21,

The coating material may be applied to the sheet of paper 11 either before or after this sheet is secured to the sheet 10, and the coating applying means of Fig. 1 is shown as acting upon the single sheet 11, while in Fig. 2 a somewhat different device is shown for applying the coating material to the sheet 11 after it has been secured to the second sheet 10. In Fig. 2 the liquid applying roller 18 is replaced by a spraying pipe 23 having a series of nozzles for spraying the coating material upon the sheet 11.

In practice it is found that the coatin material need not have an appreciable thic ness in order to impart the desired moistureproof properties to the outer sheet of paper, and that a moisture-proofing coating that is sufiiciently thin and, transparent to permit the texture of the paper to be observed therethrough gives good results.

It will be apparent from the foregoing that while the waterproofed reenforced paper above described as now on the market has the waterproof adhesive 12 that prevents moisture from penetrating entirely through the reenforced paper, this adhesive 12 does not protect an outer face of the paper 10 or 11 from the injurious action of the weather. This difficulty, however, is readily overcome in accordance with the present invention by rendering an outer face of one of the sheets 10, 11 water-repellent in the manner above described, so that when the sheet ofreenforced paperis secured'to the supporting structure of a building by nails 24 as shown. inFig. 3, the paper will be kept dry and therefore will not shrink andpull loose from the nails when exposed to the weather.

The tendency of the reenforced building paper above described as now in use, to un-' dergo a successive shrinkage action when exosed to the weather has been a serious dc.- ect, because this shrinking action would cause the marginal edges of the reenforced paper to gradually pull loose from the securing means. By protecting the exposed face of the reenforced building paper from moisture in accordancewith the. present invention the ditficulty experienced heretofore in maintaining the edges of the paper firmly secured to the supportin structureis completely overcome, and t is is accomplished without imparting to the paper an ob ectionable sticky outer surface and without appreciably increasing the weight or cost of the present paper.

What is claimed is:-

- 1. As an improved article of manufacture, a reenforced, waterproof, multiply building paper that will not shrink upon exposure to the weather sufliciently to cause the marginal edges of the paper to pull loose from the building structure to which it is secured,' comprising two sheets of moisture pervious paper secured together by a waterproof layer of asphaltum and reenforced by straightened unspun fibres secured between the sheets of paper by the asphaltum, and the sheet of the building paper that is exposed to the weather having applied to its outer face a thin water-repellent coating comprising a mixture of asphaltum and 'paraflin adapted to impart to the paper a smooth, clean, nonsticky surface without penetrating through the sheet andadapted to exclude moisture from this sheet of paper to prevent the same from shrinking the multiply paper.

2. As an improved article of manufacture a waterproof multiply building aper that will not shrink upon exposure to the weather sufliciently to cause the marginal ed es of the paper to plull loose from the buildingstructure to w 'ch it is secured, comprising two sheets of moisture pervious paper secured together by a waterproof layer of asphaltum, and the sheet of the building paper that is exposed to the weather having applied to its outer face a thin water-repellent coating comprising a mixture of asphaltum and paraflin adapted to impart to the paper I a smooth clean, non-sticky surface without penetrating through the sheet and adapted to exclude moisture from the sheet of paper to prevent the same from shrinkingthe multiply paper.

- In testimony whereof, I have signed my name to this specification. 4

GEORGE E. GIBBS. 

